| 摘要 |
Film-forming aqueous polymer dispersions are prepared by polymerizing an ethylenically unsaturated compound in aqueous emulsion in the presence of an emulsifier and of 0,1 to 10% by weight of the monomers of one or more polyvinyl alkyl ethers, which may contain hydrophilic substituents. Ether polymers specified are those of C1-C4 alkyl vinyl ethers, ethylene glycol monovinyl ether, monoethyl diethylene glycol vinyl ether, methyl vinyloxyacetate, vinyloxyethylamine and ureidoethylvinyl ether, and the products containing hydroxyl groups obtained by the partial ether-cleavage of polyvinyl alkyl ethers. Polymerizable monomers specified are styrene, vinyl and vinylidene chlorides, acrylic acid, methyl methacrylate, butyl acrylate, allyl acrylate, butanediol diacrylate, acrylamide, methacrylamide, acrylonitrile, vinyl acetate and propionate and butadiene. Emulsifiers specified are the sodium salts of alkyl benzene and paraffin sulphonates and addition products of ethylene oxide and fatty alcohols or octyl phenol. The reaction medium may also contain catalysts, e.g. persulphates, azodiisobutyronitrile and persulphates + sodium hydrogen sulphite, and dodecyl mercaptan. The examples describe the polymerization of: (1) styrene followed by the polymerization of butadiene in the polystyrene latex thus formed; (2) a mixture of acrylic acid, methyl methacrylate, butyl acrylate and acrylonitrile; (3) vinyl propionate; and (4) a mixture of methyl methacrylate and butyl acrylate. |
